Page 31 - Handbook of Electronic Assistive Technology

18 HANDBOOK OF ELECTRONIC ASSISTIVE TECHNOLOGY

having had a stroke, 30% at least to a moderate level; and around 30% will go on to have
a recurrent episode.
THROMBOTIC/EMBOLIC STROKES
• Clots and kinks/narrowing of the blood vessels have a number of risk factors, including
age, family history, obesity, diabetes, smoking and risk of heart problems (clots are
thrown off from fluttering hearts).
• Prevention is vital in people with a high risk; particularly the use of blood-thinning
agents (anticoagulation).
• Half of all ischaemic strokes involve the middle cerebral artery. Once again, extent is
variable but usually a contralateral hemiparesis and hemisensory deficit together with a
specific loss of visual field (homonymous hemianopia) is seen (weakness and sensation
problems on one side).
• If on the language dominant side (normally left) an aphasia or apraxia is seen.
• If on the nondominant side (normally right) a problem in spacial awareness is seen.

Initial rapid treatment, once a bleed has been excluded, is best provided in a specialist
unit where clot-busting therapies try to minimise low blood flow (hypoperfusion), prevent
both secondary damage from swelling of the brain and breakdown of cells releasing toxins
and also minimise risk of early recurrence.
CEREBROVASCULAR HAEMORRHAGIC STROKES
• Intracerebral (in the brain) – 10% of all strokes.
• Subarachnoid (around the brain) – 7% of all strokes.
• Though presentation is similar there are often certain clinical clues, especially headache
and vomiting, caused by the rapid increase in pressure in the skull.
• Most are secondary to high blood pressure or abnormal blood vessels (vascular
malformations – aneurysms).

Initial reduction of blood pressure and consideration of clot removal by neurosurgi-
cal teams is necessary. Recovery from stroke is dependent not only on the acute phase
of treatment but also on the input from a large interdisciplinary team to facilitate func-
tion across all modalities of thought, movement, communication and special sense
input/ output, as appropriate. This rehabilitation team utilises a wide variety of assistive
technology within long-term therapy programmes.

Tumours
• Incidence in childhood – 5/100,000/year, commonest is the solid tumour.
• Incidence in adults – 28/100,000/year.

Tumours happen at any point of the CNS. They can either be primary, from the
different cells of the nervous system, or secondary, disseminated from tumours from
other organs. Examples of primary tumours include meningiomas, glioblastomas and
astrocytomas.